Experts disagree about griz numbers, implications

Figure from the Wyoming 2002 Grizzly Management Plan

Interesting story from the Cody Enterprise..

By MARK HEINZ | Posted: Monday, October 17, 2011 3:57 pm

Grizzly numbers in the heart of the Yellowstone area habitat appeared to have dipped, but some experts’ opinions vary regarding how much, and why.

There are an estimated 593 grizzlies in the Greater Yellowstone Ecosystem, compared to 602 last year, according to a new study.

The number of bears killed, for various reasons, over the past few years “has taken a powerful bite out of the population,” said ecologist Chuck Neal of Cody, who is retired from decades of field work with the BLM, Forest Service, and contract work with the U.S. Fish and Wildlife Service.

“The take-home message is the population seems to have reached a plateau. We might be exceeding the female morality level,” said Mark Pearson, conservation program director with the Greater Yellowstone Coalition.

But Game and Fish bear expert Mark Bruscino said he thinks the population remains robust.

“The survey behind the study was only on the grizzly population in the core of the habitat, and only for one year,” he said.

“In areas where we haven’t done systematic sampling, the bear population continues to grow, both in terms of numbers and distribution. Overall, the grizzly population is doing quite well,” Bruscino said.

He was among experts and other interested parties who attended a recent meeting in Bozeman, Mont., of the Yellowstone Ecosystem subcommittee of the Interagency Grizzly Bear Committee. The IGBC includes representatives from G&F, Forest Service, Park Service, BLM, USFWS, the U.S. Geological Survey, wildlife agencies in Idaho, Montana and Washington, and Canadian Wildlife Service.

Much of the discussion centered around a population study, done mostly by USGS and USFWS researchers,

Even a slight dip in grizzly populations can be worrisome to bear experts and conservationists, because the bruins’ reproductive rates are much lower than other wildlife species.

There seems to be consensus over the idea that grizzlies are ranging farther and consequently getting into more scrapes with people. But there is some disagreement over why.

There is also differences of opinion over whether grizzlies should be delisted, and perhaps even hunted, in Wyoming.

Bruscino thinks that’s a good idea; Pearson and Neal said they want to bears retain federal endangered species protection.

A ruling from the 9th U.S. Circuit Court of Appeals on the matter is expected soon.

Looking for food?

Bears are losing some key ingredients of their diet because of the decline in white bark pine and cutthroat trout in the heart of grizzly country, Neal and Pearson said.

“Habitat quality has been in decline, primarily because of the loss of white bark pine to beetles,” Neal said.

Grizzlies like to feast on pine cone nuts, which are rich in fat and calories.

“It’s an important food source for them right now, as they fatten up for winter,” Neal said.

“We must take into consideration the effects of climate change on their food sources,” Pearson said. “With less food available in the interior habitat, bears are roaming into the fringe areas.”

Neal recalled the last time grizzlies began to disperse widely, get into trouble and, consequently, get killed in higher numbers.

That was back in the 1970s when the Park Service decided to shut down open landfills in Yellowstone, where bears had gotten accustomed to easy gorging.

Now, essentially the same thing is happening. But instead of the loss of a bad, artificial food source, grizzlies are losing natural sources, Neal said.

But Bruscino is dubious about the idea that bears are wandering to find food.

Rather, more bears are showing up in more places because they’re being pushed out by grizzlies that have laid claim to the interior habitat, he said.

Bruscino said according to what he knows, grizzlies are far more likely to adapt to new food sources in their territory, rather than wander somewhere else.

“Bears are the quintessential omnivores,” he said.

“The core habitat is saturated We just don’t see bears leaving their home ranges, he said. “Fat levels on bears in the core of the Yellowstone habitat indicate those bears are doing very well nutritionally.”

Neal said he doesn’t agree with the idea that habitat saturation is behind conflicts with people.

“They are getting into areas where people themselves are expanding their presence,” Neal said. “It’s not so much ‘saturated’ habitat,’ as it things like trying to raise chickens and sheep on the edge of occupied grizzly habitat.”

A question of tolerance

Bruscino said the GYE grizzly population has met or exceeded all the biological goals set when the recovery program started.

“We need to do more on the fringes to reduce conflicts,” he said. “In my opinion we could be hunting grizzlies, today, and it would not be detrimental to the population.”

Neal and Pearson said the answer isn’t to delist bears now, but rather to allow them to expand their habitat.

“The key has never been numbers. It’s always been enough occupied, contiguous habitat,” Neal said.

Opinions might hinge on whether people see the GYC as essentially a “island” of wild habitat, with nowhere else for grizzlies to go, or as part of a larger network of places where the bears feasibly could roam, Pearson said.

For example, GYC favors enough interconnected habitat to allow for genetic exchange between the Yellowstone and Glacier Park grizzly populations.

But he noted that conflicts with people could ultimately drive policy.

“Human tolerance is absolutely going to be the deciding factor regarding where grizzlies can thrive,” Pearson said.

California resident Dave Smith, who worked for years in Yellowstone, and still frequently visits, agreed.

“Grizzlies have been on the Endangered Species List for 30 years now, and I think people are getting worn out,” said Smith, who has written two books about staying safe around grizzlies and other large animals.

“The Game and Fish in Wyoming is having to play ‘musical bears,'” by constantly trapping and relocating troublesome grizzlies, Smith said.

This raises some questions for those that know this part of the country… given our economic situation, are folks still building houses into or next to grizzly habitat? Is critical habitat designated for private land?

I was also interested in these quotes:

Bruscino said the GYE grizzly population has met or exceeded all the biological goals set when the recovery program started.

“The key has never been numbers. It’s always been enough occupied, contiguous habitat,” Neal said.

I am not very expert on ESA, but if there are population goals, can they shift through time? That could get discouraging to people trying to implement policy
if folks are moving the goalposts.

And if the problem with endangered species is not numbers, how do we decide what is “enough occupied continguous habitat”?

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